cacos(3) BSD Library Functions Manual cacos(3)
NAME
cacos -- complex inverse cosine function
SYNOPSIS
double complex
cacos(double complex z);
long double complex
cacosl(long double complex z);
float complex
cacosf(float complex z);
DESCRIPTION
cacos(z) computes the inverse cosine of the complex floating-point number
z, with branch cuts outside the interval [-1,1] along the real axis.
cacos() returns values in a strip of the complex plane with unbounded
imaginary part, and real part in the interval [0, Pi].
For all complex floating point numbers z, cacos(conj(z)) =
conj(cacos(z)).
SPECIAL VALUES
The conjugate symmetry of cacos() is used to abbreviate the specification
of special values.
cacos(+-0 + 0i) returns Pi/2 - 0i.
cacos(+-0 + NaN i) returns Pi/2 + NaN i.
cacos(x + inf i) returns Pi/2 - inf i, for finite x.
cacos(x + NaN i) returns NaN + NaN i, for finite nonzero x.
cacos(-inf + yi) returns Pi - inf i, for finite positive-signed y.
cacos(inf + yi) returns 0 - inf i, for finite positive-signed y.
cacos(-inf + inf i) returns 3Pi/4 - inf i.
cacos(inf + inf i) returns Pi/4 - inf i.
cacos(+-inf + NaN i) returns NaN + inf i.
cacos(NaN + yi) returns NaN + NaN i, for finite y.
cacos(NaN + inf i) returns NaN - inf i.
cacos(NaN + NaN i) returns NaN + NaN i.
NOTES
SEE ALSO
complex(3)
STANDARDS
The cacos() function conforms to ISO/IEC 9899:2011.
4th Berkeley Distribution December 11, 2006 4th Berkeley Distribution
Mac OS X 10.9.1 - Generated Tue Jan 7 07:24:05 CST 2014